Innovation and entrepreneurship as the core development mode is the only way to continue my country's economic development. Therefore, research on the synergistic impact of innovation on China's ...economic development is of great significance. With the continuous development of sharing economy, Internet finance, and other fields, the digital economy is reshaping the entire social ecology and becoming an important part of the national economy. Aiming at China’s digital economy, this article takes the Shanghai Composite Index and three listed stocks in the stock market as examples, collects the closing data of the Shanghai Composite Index and the stock market prices of three listed companies as sample data, uses the BP neural network prediction model and the optimized particle swarm optimization-neural networks (PSO-BP) neural network model predicts the future trends of the Shanghai Composite Index and the three stocks, respectively. Compared with other models, PSO-BP requires fewer parameters and draws more accurate conclusions. It is a model that is very suitable for digital economic forecasting. The experimental results show that the prediction effect of the PSO-BP neural network is higher than that of the BP neural network prediction model obtained by the two prediction models in the prediction process of the Shanghai Composite Index; the error rate of the BP neural network prediction model in the three listed stocks 6.37%, 3.01%, 9.85%; PSO-BP neural network prediction model predicts the future trend of the three listed stocks with error rates of 3.21%, 0.37%, and 0.89%. After comparing and analyzing the results of the forecast error value, it is concluded that the PSO-BP neural network forecast model has a more accurate forecast of stock prices and smaller errors, and the forecast of future trends is also consistent with actual trends.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With the development of electronic technology, semiconductor memory is gradually shifting toward smaller area with less power consumption. SOT-MRAM is one of the competitive substitutes for DRAM and ...SRAM due to its superior endurance and switching speed. In contrast to STT-MRAM, the separation of read and write routes allows SOT-MRAM to have a lower error rate and higher lifetime, but this comes at the expense of the memory density. In recent years, vertical integrated circuits have relied on TSV to complete 3D stacking to ease the pressure of Moore's Law on scaling circuits. SOT-MRAM can take advantage of 3D stacking to reduce power and latency. More importantly, the density of SOT-MRAM can be improved at the same time. In the paper, simulation is conducted based on DESTINY, with the TSV model supplemented to NVSIM to evaluate the performance of MRAM 3D structures. The 3D SOT-MRAM structure in DESTINY can be implemented with a bus layer and interconnect structure between layers, which greatly reduces the expense of area. However, the 3D structure requires a more complex interconnect structure to truly meet the requirements of high density. For this reason, 3D model of unit interconnection using TSV is presented in the paper. Memory has several components, of which the memory array is the one with the largest area share. This paper explores the spatial structure of the array and proposes a new model which allows more complex interconnect structures to be accomplished on the same area.
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•Primary liver cancer incidence is still on the rise at the global level.•Pronounced increases in liver cancer incidence were mostly observed in countries with high socio-demographic ...indexes.•Liver cancer has been alleviated in some regions due to the control of HBV and HCV infections.•HCV-related liver cancer might be an important public health issue in the near future.
Liver cancer is a common malignant neoplasm worldwide. The etiologies for liver cancer are diverse and the incidence trends of liver cancer caused by specific etiologies are rarely studied. We therefore aimed to determine the pattern of liver cancer incidence, as well as temporal trends.
We collected detailed information on liver cancer etiology between 1990–2016, derived from the Global Burden of Disease study in 2016. Estimated annual percentage changes (EAPCs) in liver cancer age standardized incidence rate (ASR), by sex, region, and etiology, were calculated to quantify the temporal trends in liver cancer ASR.
Globally, incident cases of liver cancer increased 114.0% from 471,000 in 1990 to 1,007,800 in 2016. The overall ASR increased by an average 0.34% (95% CI 0.22%–0.45%) per year in this period. The ASR of liver cancer due to hepatitis B, hepatitis C, and other causes increased between 1990 and 2016. The corresponding EAPCs were 0.22 (95% CI 0.08–0.36), 0.57 (95% CI 0.48–0.66), and 0.51 (95% CI 0.41–0.62), respectively. The ASR of liver cancer due to reported alcohol use remained stable (EAPC = 0.10, 95% CI −0.06–0.25). This increasing pattern was heterogeneous across regions and countries. The most pronounced increases were generally observed in countries with a high socio-demographic index, including the Netherlands, the UK, and the USA.
Liver cancer remains a major public health concern globally, though control of hepatitis B and C virus infections has contributed to the decreasing incidence in some regions. We observed an unfavorable trend in countries with a high socio-demographic index, suggesting that current prevention strategies should be reoriented, and much more targeted and specific strategies should be established in some countries to forestall the increase in liver cancer.
Liver cancer is a common malignant neoplasm worldwide. The incidence patterns of liver cancer caused by different etiologies varied considerably across the world. In this study, we aim to determine the pattern of liver cancer incidence as well as the temporal trends, thereby facilitating the establishment of more tailored prevention strategies for liver cancer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, the magnetic immunity model of STT-MRAM is established. The influence of the external magnetic field on the effective energy barrier of STT-MRAM is investigated, which is the crucial ...issue to influence the reliability of STT-MRAM cells in the standby, active read and active write modes. The influence factors on the magnetic immunity of STT-MRAM array are also discussed in the paper, such as the electrode, package material, insert layer and array spacing, etc. Moreover, the magnetic shield models in the BGA and QFP packages are designed and analyzed for the enhancement of the magnetic immunity of STT-MRAM, whose shielding efficiency is up to 98.2%.
Electrically driven magnetization switch has attracted much attention in the new spintronic memory, especially for spin–orbit torque (SOT)-based magnetic random access memory (MRAM). However, the ...published models are facing limitations with the continuous shrinkage of the feature size down to nanoscale. Also, the thermal effect caused by switching operation is non-negligible. Therefore, an effective model is needed to represent the switching dynamic of the device concerning the influences of the nanoscale and the thermal effect. In the paper, a compact model of three-terminal SOT-driven switching is established. The influence of the voltage-controlled magnetic anisotropy (VCMA) and spin transfer torque (STT) effect induced by bias voltage on the field-free SOT-driven switching is considered by numerically solving the LLG equations. Furthermore, a 3D model of the SOT-MTJ device is established by finite element method to trace the thermoelectric behavior inside the device. The thermoelectric behavior is integrated into the compact model to show the influence of the temperature on the switching behavior, highlighting the importance of the thermal effect for the realistic modelling of SOT-driven switching. Finally, a novel voltage pulse scheme is proposed, which can effectively shorten the switching time and improve the reliability of the device. The established model could provide strategies and guidelines for next-generation memory design and application.
In the paper, novel multi-bit parallel pipeline circuit design of STT-MRAM is proposed to improve the read and write efficiency. The shift register is utilized to change the series data into the ...parallel ones. Combined with the corresponding sense amplifier (SA) circuit and the write drive circuit, 4-bit data can be read or written in parallel in single cycle. With the 32 Kbit data test, the efficiencies of the read and the write operations of the proposed pipeline circuit are increased by 72.3% and 74.4%, separately, with the comparison of the incumbent series operations. The proposed strategy has potential application in the embedded high speed STT-MRAM.
Reaction of 1 with B(C6F5)3 under 1 bar of CO2 led to the instantaneous formation of the frustrated Lewis pair (FLP)-type species ReHBr(NO)(PR3)2(η2-OCO–B(C6F5)3) (2, R = iPr a, Cy b) possessing ...two cis-phosphines and OCO2 -coordinated B(C6F5)3 groups as verified by NMR spectroscopy and supported by DFT calculations. The attachment of B(C6F5)3 in 2a,b establishes cooperative CO2 activation via the Re–H/B(C6F5)3 Lewis pair, with the Re–H bond playing the role of a Lewis base. The Re(I) η1-formato dimer {Re(μ-Br)(NO)(η1-OCHO–B(C6F5)3)(PiPr3)2}2 (3a) was generated from 2a and represents the first example of a stable rhenium complex bearing two cis-aligned, sterically bulky PiPr3 ligands. Reaction of 3a with H2 cleaved the μ-Br bridges, producing the stable and fully characterized formato dihydrogen complex ReBrH2(NO)(η1-OCHO–B(C6F5)3)(PiPr3)2 (4a) bearing trans-phosphines. Stoichiometric CO2 reduction of 4a with Et3SiH led to heterolytic splitting of H2 along with formation of bis(triethylsilyl)acetal ((Et3SiO)2CH2, 7). Catalytic reduction of CO2 with Et3SiH was also accomplished with the catalysts 1a,b/B(C6F5)3, 3a, and 4a, showing turnover frequencies (TOFs) between 4 and 9 h–1. The stoichiometric reaction of 4a with the sterically hindered base 2,2,6,6-tetramethylpiperidine (TMP) furnished H2 ligand deprotonation. Hydrogenations of CO2 using 1a,b/B(C6F5)3, 3a, and 4a as catalysts gave in the presence of TMP TOFs of up to 7.5 h–1, producing TMPHformate (11). The influence of various bases (R2NH, R = iPr, Cy, SiMe3, 2,4,6-tri-tert-butylpyridine, NEt3, PtBu3) was studied in greater detail, pointing to two crucial factors of the CO2 hydrogenations: the steric bulk and the basicity of the base.
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IJS, KILJ, NUK, PNG, UL, UM
A three-dimensional (3D) printable chipless radio frequency identification (RFID) tag, with high density and sensitivity, is proposed and fulfilled on insulator substrates. By printing a rectangular ...slot ring and designing specific geometry on the substrate, the printed structure shows high sensitivity in a resonant manner, with the benefits of high density and low cost. Considering the multiple rectangular rings with different sizes in a concentric distribution, a bit coding sequence can be observed in frequency spectra because of the corresponding different resonant frequencies aroused by the printed slots. In this way, the 3D printable chipless RFID tag can be fulfilled by adopting the structure of the rectangular slot ring on the insulated substrates. The main characteristics of the designed rectangular slot rings are verified on both flexible and solid substrates. A 12-bit chipless tag based on the slot ring structures is designed and implemented. The simulation and experiment results show good agreement on its characteristics. The frequency response reveals the fact that the 2th, 3th and 4th harmonic do not exist, which is a unique merit for improving the encoding capacity and the sensitivity of the corresponding reader. The electric field direction of the electromagnetic wave of the reader excitation tag is demonstrated to be wide, up to 90° on the tag horizontal plane, 30° on the vertical direction.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
With the introduction of the concept of land use transition into China, related researches have been carried out extensively in the past two decades, which enrich the knowledge of land system ...science. This paper describes the development of research on land use transitions in China from the perspectives of conceptual connotations, theoretical model, research methods, and research progress and prospects. With the in-depth investigation of land use transitions, the concept and connotations of land use morphology are developed and encapsulated as two kinds, i.e., dominant morphology and recessive morphology. The dominant morphology refers to the land use structure of a certain region over a certain period of time, with features such as the quantity and spatial pattern of land use types. While the recessive morphology includes the land use features in the aspects of quality, property rights, management mode, input, output and function. Accordingly, the concept of land use transition is further developed, and the theoretical model of regional land use transitions is established. Thereafter, three innovative integrated approaches to study land use transitions are put forward, i.e., multidisciplinary research framework for recessive land use transition, transect and horizontal comparison. To date, there have been 62 Ph.D. and 166 M.S. dissertations on the topic of “land use transition” in China. During 2002–2019, the National Natural Science Foundation of China has funded 48 research programs on the theme of “land use transition”. As such, the Chinese scholars have adapted the concept derived from western literature to the situations and experiences in China.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
There is increasing evidence showing that the dynamic changes in the gut microbiota can alter brain physiology and behavior. Cognition was originally thought to be regulated only by the central ...nervous system. However, it is now becoming clear that many non-nervous system factors, including the gut-resident bacteria of the gastrointestinal tract, regulate and influence cognitive dysfunction as well as the process of neurodegeneration and cerebrovascular diseases. Extrinsic and intrinsic factors including dietary habits can regulate the composition of the microbiota. Microbes release metabolites and microbiota-derived molecules to further trigger host-derived cytokines and inflammation in the central nervous system, which contribute greatly to the pathogenesis of host brain disorders such as pain, depression, anxiety, autism, Alzheimer's diseases, Parkinson's disease, and stroke. Change of blood-brain barrier permeability, brain vascular physiology, and brain structure are among the most critical causes of the development of downstream neurological dysfunction. In this review, we will discuss the following parts: Overview of technical approaches used in gut microbiome studiesMicrobiota and immunityGut microbiota and metabolitesMicrobiota-induced blood-brain barrier dysfunctionNeuropsychiatric diseases ■ Stress and depression■ Pain and migraine■ Autism spectrum disordersNeurodegenerative diseases ■ Parkinson's disease■ Alzheimer's disease■ Amyotrophic lateral sclerosis■ Multiple sclerosisCerebrovascular disease ■ Atherosclerosis■ Stroke■ Arteriovenous malformationConclusions and perspectives.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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